1. Field of the Invention
The present invention relates to a data communication system and data communication operating method. In particular, the present invention relates to a data communication system and data communication operating method which can provide a data communication service by selectively routing to a public switching telephone network (PSTN), X.25 network, and Internet by extensively applying a packet assembler deassembler (PAD) function to an interworking function device provided in a code division multiple access (CDMA) type data communication system.
2. Description of the Related Art
Generally, the network structure of an asynchronous circuit data service (service option 4,12) using the CDMA system recommended by TIA/EIA/IS-99/657/658 is illustrated in FIG. 1.
Referring to FIG. 1, a user of a mobile station requests the asynchronous circuit data service using an AT command. At this time, a mobile phone 2 combined with a data terminal 1 which can be selected among a notebook, personal digital assistant (PDA), laptop, palmtop, portable computer, compact computer, etc., may be used as the mobile station. According to the present invention, it is assumed that the data terminal is the notebook. As is well known, the mobile phone, i.e., the mobile terminal 2 seizes a base transmission station (BTS) 3, and is connected to a mobile switching center (MSC) 5 through a base station controller (BSC) 4.
A mobile subscriber processing section 51 in the mobile switching center 5 then analyzes the service option when it receives a call connection request from the mobile terminal 2. At this time, the service option may be classified in accordance with connection/disconnection of the data terminal 1 and the mobile terminal 2 and the inputted AT command. If the user requests the asynchronous circuit data service, a mobile data path is determined from a mobile data path processing section 52 of the mobile switching center 5 to a mobile data path processing section 61 of an interworking function device (IWF) 6 as a communication path. Thereafter, the mobile terminal 2 and a protocol processing section 62 of the interworking function device 6 determine a point-to-point protocol (PPP) and TCP/IP through the determined mobile data path. If the TCP/IP is determined, the mobile terminal 2 transmits the AT command, which has been recognized or has not been recognized, to an IS-99 protocol processing section 63 of the interworking function device 6.
The IS-99 protocol processing section 63 of the interworking function device 6 seizes a modem, and processes the contents recommended by the EIA/TIA/IS-99 with respect to the AT command.
Especially with respect to an ATD command, the IS-99 protocol processing section 63 analyzes a next command following the ATD command, extracts a terminating number, and then connects a call to the public switching telephone network path processing section 65 of the interworking function device 6. The public switching telephone network path processing section 65 requests the call to a public switching telephone network path processing section 54 of the mobile switching center 5 by using the terminating number extracted from the IS-99 protocol processing section 63. The public switching telephone network path processing section 54 of the mobile switching center 5 detects whether the terminating number corresponds to the terminating call to the mobile subscriber or the terminating call to the public switching telephone network by analyzing the terminating number. In case of the terminating call to the public switching telephone network 10, the public switching telephone network path processing section 54 connects the call to a wired terminal connected to the public switching telephone network 10 of the mobile switching center 5 through a trunk processing section 53 of the mobile switching center 5. However, in case of the terminating call to the mobile subscriber, the public switching telephone network path processing section 54 searches location information of the subscriber by communicating with a home location register (HLR) or a visitor location register (VLR). At this time, if the terminating call is the call for the subscriber of the intra mobile switching center as the result of search, the public switching telephone network path processing section 54 connects the call to the interworking function device 6 through the public switching telephone network path processing section 54 of the mobile switching center, while if the terminating call is the call for the subscriber of the inter mobile switching center, it connects the call to another mobile switching center through the trunk processing section 53.
However, according to the conventional network structure, only the calls with the public switching telephone network 10 can be processed in case of the asynchronous circuit data service (service option 4, 12). Accordingly, in the CDMA type data communication system, the data communication service with the X.25 network and Internet, which are generally used, cannot be provided by the asynchronous circuit data service option.
Further, the user should necessarily input the terminating number in order to receive the CDMA asynchronous circuit data service, and should remember the IP server connection numbers in order to connect with the IP servers of the public switching telephone network 10, using the asynchronous circuit data service.
Furthermore, in order for the user to process the terminating call to the public switching telephone network 10, a waiting time which is longer than that in the wired network is required for identifying the connection state with a wired terminal connected to the public switching telephone network. Specifically, the connection time between the mobile station and the mobile switching center 5, and the protocol negotiation time between the protocol processing section 62 of the interworking function device 6 and the mobile terminal 2 are required. The negotiation time may be varied according to the radio environment, and may be about 4 to 10 seconds. Also, the negotiation time between the modem 64 of the interworking function device 6 and the modem 7 connected to the public switching telephone network 10 may be about 7 to 10 seconds.
Accordingly, the present invention is directed to a data communication system and data communication operating method that substantially obviate one or more of the problems due to limitations and disadvantages of.the related art.
An object of the present invention is to provide a data communication system and data communication operating method which can provide data communication service to a public switching telephone network, X.25 network, and Internet by extensively applying a packet assembler deassembler (PAD) function to an interworking function device of a CDMA type data communication system.
It is another object of the present invention to provide a data communication system and data communication operating method which can receive an asynchronous circuit data service without inputting a terminating number, and which can connect with an IP server of a public switching telephone network using an asynchronous circuit data service without the necessity of remembering an IP server connection number.
It is still another object of the present invention to provide a data communication system and data communication operating method which can provide a waiting time faster than that in a wired network in case of identifying the connection state with a wired terminal connected to a public switching telephone network.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the data communication system is characterized in that if a certain mobile station requests a data service, the data communication system analyzes the condition of terminating information inputted by a user of the mobile station, and selectively connects the mobile station to a public switching telephone network, X.25 network, and Internet.
In another aspect of the present invention, there is provided a data communication operating method comprising the steps of determining a data transmission path between a certain mobile station and an interworking function device if the mobile station requests a data service, analyzing the condition of terminating information inputted by a user of the mobile station, and selectively connecting the mobile station to a public switching telephone network, X.25 network, and Internet according to the result of analyzing the condition of terminating information.
According to the present invention as described above, a mobile station can be selectively connected to a public switching telephone network, X.25 network, and Internet by extensively applying a PAD function to an interworking function device during an asynchronous circuit data service. Also, a menu for connecting with a host server of the X.25 network, Internet, and public switching telephone network is provided to a terminal user by applying an extensive terminal number analyzing function to the PAD, and thus a call from the mobile station is connected to the respective host server of the X.25 network, Internet, and public switching telephone network if the menu is selected, while the call is connected to a mobile switching center if another number is inputted. Also, according to the present invention, it is not required for the user to remember the connection number of the host server. Specifically, since the connection menu is transmitted from the PAD of the interworking function device to the terminal user before the complete connection to the wired network, the terminal user can receive a response menu faster than the wired network, thereby enabling a very convenient data service.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.